Overview
The reader and writer interfaces define the contract for reading from and writing to different Minecraft world formats. These interfaces are implemented by format-specific classes for Java Edition and Bedrock Edition.
LevelReader
Interface for reading world data from a specific format.
Interface Definition
package com.hivemc.chunker.conversion.encoding.base.reader;
public interface LevelReader extends LevelReaderWriter
cli/src/main/java/com/hivemc/chunker/conversion/encoding/base/reader/LevelReader.java:12
Methods
readLevel()
Read the level data and invoke the handler with the results.
void readLevel(LevelConversionHandler levelConversionHandler) throws Exception
levelConversionHandler
LevelConversionHandler
required
The handler to receive the level data, world data, and chunk data as it’s read
Exception if an error occurs during reading
Location: LevelReader.java:18
readCustomLevelSetting()
Read a custom level setting annotated as custom (format-specific).
@Nullable
default Object readCustomLevelSetting(
@NotNull CompoundTag root,
@NotNull String targetName,
@NotNull Class<?> type
)
The root NBT tag containing the settings
The name of the custom setting to read
The expected type of the setting value
IllegalArgumentException by default - must be overridden to support custom settings
Location: LevelReader.java:28
getWarnings()
Get any warnings generated during the read process.
@Nullable
default String getWarnings()
LevelReader.java:38
isReader()
Check if this is a reader instance.
default boolean isReader()
true for readers
Location: LevelReader.java:33
Inherited Methods (from LevelReaderWriter)
getEncodingType()
Get the encoding type this reader handles.
EncodingType getEncodingType()
EncodingType.JAVA or EncodingType.BEDROCK)
getVersion()
Get the Minecraft version this reader detected.
Returns: The detected version of the world
free()
Clean up resources when conversion is complete.
default void free() throws Exception
cli/src/main/java/com/hivemc/chunker/conversion/encoding/base/LevelReaderWriter.java:33
LevelWriter
Interface for writing world data to a specific format.
Interface Definition
package com.hivemc.chunker.conversion.encoding.base.writer;
public interface LevelWriter extends LevelReaderWriter
cli/src/main/java/com/hivemc/chunker/conversion/encoding/base/writer/LevelWriter.java:13
Methods
writeLevel()
Write the level data and return a world writer for writing world-specific data.
WorldWriter writeLevel(ChunkerLevel chunkerLevel) throws Exception
The level data to write (including settings, seed, spawn point, etc.)
A world writer instance for writing dimension and chunk data
Exception if an error occurs during writing
Location: LevelWriter.java:21
flushLevel()
Called when all level writing is complete. Used for final cleanup and flushing.
default void flushLevel() throws Exception
Exception if an error occurs during flushing
Location: LevelWriter.java:28
writeCustomLevelSetting()
Write a custom level setting annotated as custom (format-specific).
default void writeCustomLevelSetting(
ChunkerLevelSettings chunkerLevelSettings,
CompoundTag output,
String targetName,
Object value
)
chunkerLevelSettings
ChunkerLevelSettings
required
The level settings object
The output NBT tag to write the setting to
The name of the custom setting
IllegalArgumentException by default - must be overridden to support custom settings
Location: LevelWriter.java:40
Get the pre-transform manager for this writer (used for block connections).
@Nullable
default PreTransformManager getPreTransformManager()
LevelWriter.java:50
isReader()
Check if this is a reader instance.
default boolean isReader()
false for writers
Location: LevelWriter.java:45
Inherited Methods (from LevelReaderWriter)
Same as LevelReader - see above.
WorldWriter
Interface for writing world (dimension) data.
Interface Definition
package com.hivemc.chunker.conversion.encoding.base.writer;
public interface WorldWriter
cli/src/main/java/com/hivemc/chunker/conversion/encoding/base/writer/WorldWriter.java:8
Methods
writeWorld()
Write world information and return a column writer for writing chunks.
ColumnWriter writeWorld(ChunkerWorld chunkerWorld) throws Exception
The world data to write (dimension type, generator settings, etc.)
A column writer for writing chunk data in this world
Exception if an error occurs during writing
Location: WorldWriter.java:16
flushWorld()
Called when a world has finished being written.
default void flushWorld(ChunkerWorld chunkerWorld) throws Exception
The world that finished writing
Exception if an error occurs during flushing
Location: WorldWriter.java:24
flushWorlds()
Called when all worlds have been written.
default void flushWorlds() throws Exception
Exception if an error occurs during flushing
Location: WorldWriter.java:33
Usage Examples
Creating a Reader
import com.hivemc.chunker.conversion.encoding.EncodingType;
import com.hivemc.chunker.conversion.encoding.base.reader.LevelReader;
import java.io.File;
// Create a reader for a Java world
File worldDir = new File("path/to/java/world");
LevelReader reader = EncodingType.JAVA
.createReader(worldDir, converter)
.orElseThrow(() -> new IllegalArgumentException(
"Could not read world - unknown version or corrupted data"
));
// Check the detected version
System.out.println("World version: " + reader.getVersion());
System.out.println("Format: " + reader.getEncodingType().getName());
// Get any warnings
String warnings = reader.getWarnings();
if (warnings != null) {
System.out.println("Warnings: " + warnings);
}
Creating a Writer
import com.hivemc.chunker.conversion.encoding.EncodingType;
import com.hivemc.chunker.conversion.encoding.base.Version;
import com.hivemc.chunker.conversion.encoding.base.writer.LevelWriter;
import java.io.File;
// Create a writer for Bedrock 1.20.0
File outputDir = new File("path/to/output");
Version targetVersion = new Version(1, 20, 0);
LevelWriter writer = EncodingType.BEDROCK
.createWriter(outputDir, targetVersion, converter)
.orElseThrow(() -> new IllegalArgumentException(
"Bedrock version " + targetVersion + " is not supported"
));
// Check the target version
System.out.println("Writing to version: " + writer.getVersion());
System.out.println("Format: " + writer.getEncodingType().getName());
Using with WorldConverter
import com.hivemc.chunker.conversion.WorldConverter;
import com.hivemc.chunker.conversion.encoding.EncodingType;
import com.hivemc.chunker.conversion.encoding.base.Version;
import java.util.UUID;
// Create converter
WorldConverter converter = new WorldConverter(UUID.randomUUID());
converter.setProcessMaps(true);
converter.setProcessEntities(true);
// Auto-detect input format
LevelReader reader = EncodingType.findReader(
new File("path/to/input"),
converter
).orElseThrow();
// Create output writer
LevelWriter writer = EncodingType.BEDROCK.createWriter(
new File("path/to/output"),
new Version(1, 20, 0),
converter
).orElseThrow();
// Start conversion
TrackedTask<Void> task = converter.convert(reader, writer);
task.getFuture().join();
System.out.println("Conversion complete!");
import com.hivemc.chunker.conversion.encoding.EncodingType;
import java.io.File;
// Automatically detect and create appropriate reader
File unknownWorld = new File("path/to/world");
LevelReader reader = EncodingType.findReader(unknownWorld, converter)
.orElseThrow(() -> new IllegalArgumentException(
"Could not detect world format. Supported formats: Java, Bedrock"
));
String format = reader.getEncodingType().getName();
String version = reader.getVersion().toString();
System.out.println("Detected " + format + " Edition v" + version);
Constructor Interfaces
EncoderLevelReaderConstructor
Functional interface for creating readers.
package com.hivemc.chunker.conversion.encoding;
@FunctionalInterface
public interface EncoderLevelReaderConstructor<T extends LevelReader> {
Optional<? extends T> construct(File inputDirectory, Converter converter);
}
cli/src/main/java/com/hivemc/chunker/conversion/encoding/EncoderLevelReaderConstructor.java:14
EncoderLevelWriterConstructor
Functional interface for creating writers.
package com.hivemc.chunker.conversion.encoding;
@FunctionalInterface
public interface EncoderLevelWriterConstructor<T extends LevelWriter> {
Optional<? extends T> construct(
File outputDirectory,
Version outputVersion,
Converter converter
);
}
cli/src/main/java/com/hivemc/chunker/conversion/encoding/EncoderLevelWriterConstructor.java:15
See Also